Railway snow melter duct assembly

ABSTRACT

The present disclosure relates to a component for a railway snow melter. The component includes a mounting plate adapted for connection to a tie duct. The mounting plate defines a point nozzle opening and/or a track duct nozzle. A point nozzle is mounted to the mounting plate at a location above the point nozzle opening. A track duct nozzle is mounted to the mounting plate at a location above the track duct nozzle opening.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/597,008 filed Aug. 28, 2012, which is a divisional of U.S.application Ser. No. 11/906,538 filed Oct. 2, 2007 and issued as U.S.Pat. No. 8,251,320 on Aug. 28, 2012, which claims the benefit of U.S.Provisional Patent Application Ser. No. 60/849,640 filed Oct. 4, 2006,which applications are incorporated herein by reference in theirentireties.

TECHNICAL FIELD

The present invention relates generally to railway equipment. Moreparticularly, the present invention relates to equipment for use withhot air blowers for melting snow and ice at railway switch points orother locations.

BACKGROUND

FIG. 1 shows a prior art railway switch 10. The switch 10 includes fixedrails 22 a and 24 a secured to railroad ties 26. The switch layout 10also includes switching rails 22 b and 24 b positioned inside the fixedrails 22 a, 24 a. An actuator 28 is provided for moving the switchingrails 22 b, 24 b between a first position (shown in FIG. 1) and a secondposition (not shown). In the first position, the switching rail 22 bcontacts the fixed rail 22 a and the switching rail 24 b is offset fromthe fixed rail 24 a. In the second position, the switching rail 22 b isoffset from the fixed rail 22 a, and the switching rail 24 b contactsthe fixed rail 24 a. The actuator 28 is linked to the switching rails 22b, 24 b by a throw rod 30.

In northern climates, snow and ice can accumulate at the switch 10 andthereby interfere with the movement of the switching rails 22 b, 24 bbetween the first and second positions. To prevent the accumulation ofsnow and ice, a hot air blower 32 is provided for melting snow and iceat the switch 10. A duct assembly 34 carries hot air from the blower 32to the switch 10. The duct assembly 34 includes a lateral duct 36, a tieduct 38, inner track ducts 40 and outer track ducts 42 (only one shown).The lateral duct 36 extends from the blower 32 to the tie duct 38. Thetie duct 38 extends beneath the fixed rails 22 a, 24 a, and supports therails 22 a, 24 a. The inner track ducts 40 extend generallyperpendicularly outwardly from the tie duct 38. The inner track ducts 40are positioned inside the switching rails 22 b, 24 b and are generallyparallel to the switching rails 22 b, 24 b. The outer track ducts 42also extend perpendicularly outwardly from the tie duct 38. The outertrack ducts 42 are positioned outside the fixed rails 22 a, 24 a and aregenerally parallel to the fixed rails 22 a, 24 a. The track ducts 40, 42are connected to the tie duct 38 by track duct nozzles 44. The trackducts 40, 42 include punch-outs (not shown) where holes can be formedfor directing hot air from the track ducts 40, 42 toward selectedlocations of the switch 10. The duct assembly 34 can also include pointnozzles 46 coupled to the tie duct 38. The point nozzles 46 function todirect hot air at the contact points between the fixed rails 22 a, 24 aand the switching rails 22 b, 24 b.

FIGS. 2 and 3 show the tie duct 38 in more detail. Generally, the tieduct 38 is a railroad tie-shaped duct constructed of a material such asmetal. The tie duct 38 has a hollow, generally rectangular cross-sectionand has end flanges 48 for coupling either end of the tie duct 38 to thelateral duct 36. As depicted in FIGS. 2 and 3, the ends of the tie duct38 are enclosed by end plates 39. When the tie duct 38 is installed at arailway site, at least one of the end plates 39 is removed prior toattaching the lateral duct 36 to the corresponding end flange 48 of thetie duct 38 so that fluid communication is provided between the interiorof the lateral duct 36 and the interior of the tie duct 38.

Referring still to FIGS. 2 and 3, the fixed rails 22 a, 24 b are securedto the tie duct 38 by a conventional rail fastening arrangement. Forexample, as shown at FIGS. 2 and 3, the fixed rails 22 a, 24 a aresecured to the tie duct 38 by tie plates 50 fastened to the top side ofthe tie duct 38, and e-clips 52 that link the tie plates 50 to the fixedrails 22 a, 24 a so that the rails are fixed to the top sides of the tieplates 50.

The top side of the tie duct 38 also defines openings for providingfluid communication between the hollow interior of the tie duct 38 andthe inner track ducts 40, the outer track ducts 42, and the pointnozzles 46. For example, openings 54 in the tie duct 38 provide fluidcommunication with the outer track ducts 42, openings 56 in the tie duct38 provide fluid communication with the inner track ducts 40, andopenings 58 in the tie duct 38 provide fluid communication with thepoint nozzles 46. When the track ducts 40, 42 or the point nozzles 46are not installed on the tie duct 38, cover plates 60 (shown mountedover the openings 54) can be mounted over the openings 54, 56 or 58 toprevent debris from entering the interior of the tie duct 38.

Referring to FIGS. 4-6, the point nozzles 46 are fastened to the topwall of the tie duct 38 at locations over the openings 58. Preferably,the point nozzles 46 are fastened to the tie duct 38 by a fasteningarrangement that electrically isolates the point nozzles 46 from the tieduct 38. As shown at FIGS. 4 and 5, the fastening arrangement includesbolts 62 that extend through curved openings 64 defined by a bottomflange 66 of the point nozzle 46. The bolts 62 are typically threadedwithin tapped openings 63 defined through a top wall 65 of the tie duct38. A screen 68 is mounted at the top side of the tie duct 38. Thescreen 68 covers the opening 58 to prevent animals (e.g., rodents) ordebris from entering the interior of the tie duct 38. A dielectricgasket 70 is mounted between the screen 68 and the bottom flange 66. Thegasket 70 has a shape that generally matches the shape of the bottomflange 66 and functions to electrically isolate the flange 66 from thetop side of the tie duct 38. The bolts 62 are also preferablyelectrically isolated from the point nozzle 46. As shown at FIG. 4, adielectric bushing/spacer 72 isolates the shank of the bolt 62 from thebottom flange 66, and a dielectric washer 74 electrically isolates thehead of the bolt 62 from the point nozzle 46. The fastening assemblyalso includes a flat washer 76 positioned below the dielectric washer74, a flat washer 78 positioned above the dielectric washer 74, and asplit lock washer 80 positioned between the flat washer 76 and the headof the bolt 62. It will be appreciated that four of the bolt fasteningassemblies are provided for each of the point nozzles 46.

Fastening arrangements are also used to fasten the track duct nozzles 44to the top wall of the tie duct 38. The track duct nozzles 44corresponding to the inner track ducts 40 are mounted over the openings56, and the track duct nozzles 44 corresponding to the outer track ducts42 are mounted over the openings 54. Similar to the point nozzles 46, itis desirable for the track duct nozzles 44 to be electrically isolatedfrom the tie duct 38.

Referring to FIGS. 7-9, an example fastening arrangement for securingthe track duct nozzles 44 to the top wall 65 of the tie duct 38 isshown. The fastening arrangement includes a plurality of bolts 82 thatare mounted through openings 84 defined through a bottom flange 86 ofthe track duct nozzle 44. Typically, the bolts 82 are threaded withintapped openings 67 defined through the top wall 65 of the tie duct 38. Adielectric gasket 90 having a shape that generally matches the shape ofthe bottom flange 86 is mounted beneath the bottom flange 86. The gasket90 functions to electrically insulate the bottom flange 86 from the topside of the tie duct 38. A screen 88 is mounted between the gasket 90and the top side of the tie duct 38. The screen 88 prevents animals ordebris from entering the interior of the tie duct 38. The bolts 82 arealso preferably electrically isolated from their corresponding trackduct nozzles 44. For example, as shown at FIG. 7, a dielectricspacer/bushing 92 and a dielectric washer 94 are provided for each bolt82. The dielectric spacers/bushings 92 isolate the shanks of the bolts82 from the bottom flange 86, and the dielectric washers 94 electricallyisolate the heads of the bolts 82 from the bottom flanges 86. Thefastening assemblies also include a flat washer 98 positioned above eachdielectric washer 94, and a split lock washer 100 positioned betweeneach flat washer 98 and the head of each corresponding bolt 82. Adhesive101 can be used to provide a seal at the interface between the trackduct nozzles 44 and the track ducts 40 and 42.

SUMMARY

The present disclosure relates to systems and methods for facilitatingconnecting and disconnecting snow melter duct nozzles to tie ducts.Systems and methods in accordance with the principles of the presentdisclosure allow snow melting systems for use at railway locations to beassembled in the field more efficiently. This provides significant timesavings during initial installation of the snow melter. Additionally,the invention provides substantial time savings when the snow melterduct work is disassembled to permit tamping operations, and thenreassembled.

A variety of additional inventive aspects will be set forth in thedescription that follows. The inventive aspects can relate to individualfeatures and to combinations of features. It is to be understood thatboth the foregoing general description and the following detaileddescription are exemplary and explanatory only and are not restrictiveof the broad inventive concepts upon which the embodiments disclosedherein are based.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top, plan view of a prior art railroad switch layout;

FIG. 2 is a top, plan view of a prior art tie duct used in the switchlayout of FIG. 1;

FIG. 3 is a side view of the tie duct of FIG. 2;

FIG. 4 is an exploded view of one of the point nozzles mounted on thetie duct of FIGS. 2 and 3;

FIG. 5 is a cross-sectional view taken along a section line cuttransversely through one of the point nozzles mounted on the track ductof FIGS. 2 and 3;

FIG. 6 depicts a bag containing fastening components used to secure thepoint nozzle of FIG. 4 to the tie duct of FIGS. 2 and 3;

FIG. 7 is an exploded view of one of the track duct nozzles that ismounted to the top side of the tie duct of FIGS. 2 and 3;

FIG. 8 illustrates a bag containing components used to fasten the trackduct nozzle of FIG. 7 to the tie duct of FIGS. 2 and 3;

FIG. 9 is a cross-sectional view taken along a section line cuttransversely through one of the track duct nozzles mounted on the trackduct of FIGS. 2 and 3;

FIG. 10 is a top, plan view of a tie duct having inventive features inaccordance with the principles of the present disclosure;

FIG. 11 is a side view of the tie duct of FIG. 10;

FIG. 12 is a top, plan view of a duct nozzle unit having inventivefeatures in accordance with the principles of the present disclosure;

FIG. 13 is an exploded view of the duct nozzle unit of FIG. 12;

FIG. 14 is a plan view of a plate that is a component of the duct nozzleunit of FIGS. 12 and 13;

FIG. 15 is a cross-sectional view taken lengthwise through one of theembedded fasteners of the plate of FIG. 14; and

FIG. 16 is a plan view of an alternative mounting plate having featuresin accordance with the principles of the present disclosure.

DETAILED DESCRIPTION

It is often necessary to assemble and disassemble hot air snow melterduct work many times in the field. For example, the duct work is firstassembled during initial installation to a tie duct at a switch point.After initial assembly, it is required to periodically tamp theaggregate provided between the railroad ties at the switch point tomaintain track integrity. To adequately tamp the aggregate at the switchpoint, the duct work is typically removed from the tie duct to provideaccess to the aggregate beneath the duct work. After tamping, the ductwork needs to be reassembled. It is also common for duct work to bedamaged by passing trains. Each time duct work is substantially damaged,the damaged duct work needs to be disconnected from its correspondingtie duct and replaced with new duct work.

The disassembly and assembly of snow melter duct work typically requiresat least a two person crew because one crew member conducts thedisassembly and assembly and the other crew member maintains constantlookout for approaching trains. While the crew is working on a sectionof track, it is necessary for the section of track to be shut down. Thisinterferes with train scheduling and routing.

Conventional fastening assemblies used to secure the point nozzles andthe track duct nozzles to a tie duct have many parts that must behandled in the field. Due to the large number of parts that must behandled, the assembly and disassembly of snow melter duct work in thefield can be quite time consuming. Time spent on the assembly anddisassembly of duct work can amount to significant cost because of themanpower required to conduct the assembly/disassembly and theinconvenience associated with track closures.

One aspect of the present disclosure relates to a system/method forsimplifying the assembly and disassembly of hot air snow melter ductwork in the field. In one embodiment, at least one nozzle is pre-mountedto an intermediate mounting plate. For example, the nozzle can bemounted to the mounting plate before the nozzle is delivered to thefield, or can be mounted to the mounting plate before the section oftrack at which the nozzle is intended to be installed is shut down forinstallation of the nozzle. The mounting plate is preferably anintermediate piece (e.g., an adapter) positioned between the nozzle andthe tie duct that provides a simple mechanical interface with the tieduct. The mounting plate preferably can be connected to the tie duct anddisconnected from the tie duct without disturbing the fixed rails. Inone embodiment, the mounting plate is attached to the tie duct at alocation between the tie plates that support the rails.

When the nozzle is installed on the tie duct, it is preferred for thenozzle to be electrically isolated from the tie duct. For example, ifthe mounting plate is constructed of an electrically conductivematerial, it is preferred that the nozzle be secured to the mountingplate by a fastening arrangement that electrically isolates the nozzlefrom the mounting plate. By electrically isolating the nozzle from themounting plate, the nozzle is also electrically isolated from the tieduct. In alternative embodiments, the nozzle can be electricallyisolated from the tie duct by using a mounting plate having a dielectricconstruction.

FIGS. 10 and 11 illustrate an assembly having features that are examplesof inventive aspects in accordance with the principles of the presentdisclosure. The assembly includes a tie duct 138 that can be substitutedfor the tie duct 38 of FIG. 1. First and second nozzle units 200 aremounted to the top wall of the tie duct 138. Each nozzle unit 200includes a mounting plate 202 fastened to the top wall of the tie duct138. Each nozzle unit 200 also includes a point nozzle 46 and track ductnozzle 44 fastened to the mounting plate 202. In this way, the mountingplate 202 forms an intermediate structure positioned between the tieduct 138 and the nozzles 44, 46. The track duct nozzle 44 and the pointnozzle 46 are preferably electrically isolated from their correspondingmounting plates 202. In typical embodiments, the mounting plates 202 arenot electrically isolated from the tie duct 138. The nozzle units 200greatly facilitate assembling and disassembling snow melter systems inthe field. For example, the nozzle units 200 can be preassembled in thefactory prior to being delivered to the field. Therefore, when thenozzle units 200 are delivered to the field, it is not necessary for thefield technician to handle all of the fasteners corresponding to each ofthe separate nozzles 44, 46. Instead, the nozzle units 200 are quicklyfastened to the track duct 138 in the field with a relatively smallnumber of fasteners. The nozzle units 200 allow multiple nozzles 44, 46to be fastened to or unfastened from the tie duct 138 at one time with areduced number of fasteners, thereby greatly facilitating theassembly/disassembly process.

It is preferred for the mounting plates 202 to be configured forattachment to the top side of the tie duct 138. For example, in oneembodiment the mounting plates 202 have a generally flat bottom sideadapted to seat on the top side of the tie duct 138. Additionally, eachmounting plate 202 includes a plurality of fastener holes 204 (see FIG.14) adapted to receive fasteners that secure the mounting plates 202 tothe top side of the tie duct 138. In the depicted embodiment, eachmounting plate 202 includes four fastener holes 204 with each fastenerhole being located adjacent to a corner of the mounting plate 202. Itwill be appreciated that the fasteners used to secure the mountingplates 202 to the tie duct 138 can include bolts 206 that are insertedthrough the fastener holes 204 and threaded into corresponding tappedopenings defined through the top wall of the tie duct 138. Otherfasteners could also be used.

In the depicted embodiment, the mounting plates 202 are sized to fitbetween the fixed rails 22 a, 24 a of the railway. In this way, themounting plates 202 can be mounted between the tie plates 50 and can beconnected to and disconnected from the tie duct 138 without disturbingthe fixed rails supported by the tie plates 50. In one embodiment, eachmounting plate 202 can have a width W generally equal to the width ofthe tie duct 138 (e.g., about 8-10 inches). In some embodiments it isalso preferred for the mounting plates 202 to have lengths that areshorter than the distance between the fixed rails 22 a, 24 a. In thedepicted embodiment in which two nozzles are mounted to the mountingplate, it is preferred that each mounting plate has a length less thanor equal to about 28.25 inches. In other embodiments, more than twonozzles can be mounted on a mounting plate. For example, in oneembodiment, the two inner track duct nozzles and the two point nozzlesare all mounted on one mounting plate. For such an embodiment, themounting plate preferably has a length less than 56.5 inches.

As depicted in the example embodiment shown at FIGS. 13 and 14, eachmounting plate 202 has a generally flat, rectangular plate construction.In an example embodiment, each plate 202 can be constructed of a metalmaterial such as steel. Each plate 202 preferably defines openings 156,158 adapted to respectively align with corresponding openings 56, 58defined through the top wall of the tie duct 138. In this way, themounting plates 202 do not substantially interfere with the fluidcommunication provided between the interior of the tie duct 138 and theinteriors of the nozzles 44, 46. It will be appreciated that the numberof openings provided in the mounting plate and its corresponding tieduct can be varied without departing from the principles of the presentdisclosure. Similarly, the size and shape of the openings provided inthe mounting plate and its corresponding tie duct can be varied withoutdeparting from the principles of the present disclosure. Any mountingplate configuration that provides fluid communication between thenozzles and the hollow interior of the tie duct is within the scope ofthe present disclosure.

Referring again to FIGS. 13 and 14, fasteners 162 are provided forfastening the point nozzle 46 to the mounting plate 202, and fasteners182 are provided for fastening the track duct nozzle 44 to the mountingplate 202. In the depicted embodiment, each of the fasteners 162, 182includes a threaded stud 300 that projects upwardly from the top side ofthe mounting plate 202. In preferred embodiments, the studs 300 do notproject below the bottom surface of the mounting plate 202 so as to notinterfere with flush mounting of the mounting plates 202 on the tie duct138. In a preferred embodiment, mounting ends of the studs are fixedlysecured (e.g., welded, press fit, or otherwise attached) within verticalopenings defined by the mounting plate 202 (see FIG. 15).

For each nozzle unit 200, it is preferred in some embodiments for thepoint nozzle 46 and the track duct nozzle 44 to be electrically isolatedfrom their corresponding mounting plate 202. As shown at FIG. 13, thepoint nozzle 46 can be isolated from the mounting plate 202 by a gasket70, and fasteners 162 are isolated from the point nozzle 46 bydielectric spacers/bushings 72 and by dielectric washers 74. The trackduct nozzle 44 is electrically isolated from the mounting plate 202 by agasket 90. Fasteners 182 are electrically isolated from the track ductnozzle 44 by dielectric spacers/bushings 92 and by dielectric washers94.

In some embodiments, it is preferred for the track duct nozzle 44 andthe point nozzle 46 to be mounted to their corresponding mounting plate202 prior to delivering the nozzle unit 200 to the field. For example,the nozzle unit 200 can be assembled at the factory. To mount the pointnozzle 46 to the mounting plate 202, a screen 68 is positioned over theopening 158 defined through the mounting plate 202. In accordance withthe depicted embodiment, the gasket 70 is then positioned on top of thescreen 68 and surrounding the opening 158. The point nozzle 46 is thenmounted on the plate 202 by positioning the point nozzle 46 such thatthe fasteners 162 extend through the curved openings 64 defined by thebottom flange 66 of the point nozzle 46. Spacer 72, flat washer 76,dielectric washer 74, flat washer 78 and split lock washer 80 are thenconsecutively positioned over each of the fasteners 162. Nuts 209 arethen threaded on the threaded ends of the fasteners 162 to complete theassembly process.

The track duct nozzle 44 can be secured to the mounting plate 202 in asimilar manner. For example, screen 88 is first positioned over opening156. Next, gasket 90 is positioned over screen 88 and around the opening156. The track duct nozzle 44 is then positioned on the gasket 90. Thetrack duct nozzle 44 is preferably aligned such that the fasteners 182extend through the openings 84 defined by the bottom flange 86 of thetrack duct nozzle 44. Thereafter, the dielectric spacer 92, thedielectric washer 94, the flat washer 98 and the split lock washer 100are respectively positioned on each of the fasteners 182. The assemblyprocess is completed by threading nuts 209 on the threaded ends of thefasteners 182.

By pre-connecting the track duct nozzle 44 and the point nozzle 46 tothe mounting plate 202, the amount of assembly that is required to becompleted in the field is substantially reduced. Rather than handlingall of the separate fasteners, washers and dielectric elementscorresponding to each of the separate nozzles 44, 46, the fieldtechnician only handles the reduced number of fasteners used to secureeach mounting plate 202 to the tie duct 38. In the depicted embodiment,the field technician need only handle four bolts for each of the nozzleunits 200. Of course, the number of attachment fasteners used for eachnozzle unit can be varied without departing from the principles of thepresent invention. By using preassembled sub-assemblies, the variousaspects of the present invention allow railway snow melters to beassembled and disassembled more efficiently. The sub-assemblies allowmultiple nozzles to be removed or attached to a tie duct at the sametime as a unit. This greatly reduces the number of individual parts thatneed to be handled by the field technician.

In alternative embodiments, the mounting plate of the nozzle unit canhave a dielectric construction. For example, the mounting plate may beconstructed of a dielectric material such as a plastic material, acomposite material or other materials. In still other embodiments, themounting plate may include an electrically conductive member that iscoated or encased within a dielectric outer layer. Such configurationsmay eliminate the need for using dielectric spacers and dielectricwashers in combination with the fasteners that secured the nozzles tothe mounting plate.

FIG. 16 shows another mounting plate 202′ in accordance with theprinciples of the present disclosure. The mounting plate 202′ hasfastener holes 204′ configured to receive fasteners such as bolts thatare used to secure the mounting plate 202′ to its corresponding tieduct. The holes 204′ are configured to allow the mounting plate 202′ tobe disconnected from its corresponding tie duct by merely loosening thefasteners used to secure the mounting plate 202′ to the tie duct. Oncethe fasteners are loosened, the mounting plate 202′ can be manipulated(e.g., pivoted and slid) to disengage the fasteners from the openings.In this way, the fasteners need not be completely disconnected from thetie duct to remove the mounting plate from the tie duct.

The above specification provides examples of how certain inventiveaspects may be put into practice. It will be appreciated that theinventive aspects can be practiced in other ways than those specificallyshown without departing from the spirit and scope of the inventiveaspects.

What is claimed is:
 1. A method of directing hot air from a snow melterto rails of a railway line comprising: positioning a tie duct under andacross a pair of rails of a railway line, the tie duct defining an innerpassage configured to direct air flow; connecting the tie duct to ablower of the snow melter; connecting a preassembled nozzle and mountingplate unit to a top surface of the tie duct between the pair of rails;and connecting track ducts to the nozzle.
 2. The method of claim 1,wherein the pair of rails are fixed rails and the tie duct is connectingthe pair of fixed rails.
 3. The method of claim 1, wherein thepreassembled nozzle and mounting plate unit includes a plurality ofnozzles fixed to a single mounting plate.